CVE-2026-68253

What it actually does

The vulnerability allows a buffer overflow in the drm/i915/hdcp kernel code because the bounds check on data->streams[] occurs after data has already been written past the end of the array.

Why it matters to the business

Systems using Intel integrated graphics with HDCP enabled risk kernel instability or memory corruption that can lead to crashes, denial of service, or potential privilege escalation, requiring urgent kernel updates to avoid operational disruption.

How an attack unfolds

An attacker supplies crafted HDCP stream data that exceeds the allocated size of the streams array; the kernel writes beyond the buffer before the bounds check runs, resulting in memory corruption that can be leveraged for further exploitation.

How to fix it

Apply the upstream kernel fix that moves the streams[] bounds check before any write operation; rebuild or install the patched kernel version containing commit 9284ab3b6e776c315883ac2611283d263c9460fd or equivalent backport.

How to confirm the fix worked

Inspect the drm/i915/hdcp source to confirm the bounds check precedes the array write, or verify the running kernel contains the referenced commit and test HDCP stream handling with boundary values.

Typical attack path

1. Identify a target system with Intel i915 graphics and HDCP support enabled
2. Trigger the vulnerable HDCP stream handling code path with oversized stream metadata
3. Cause out-of-bounds write into kernel memory
4. Leverage resulting corruption for privilege escalation or denial of service

How to detect it

Search kernel logs for i915 or HDCP related warnings, backtraces, or oops messages occurring around the time of suspected exploitation; examine dmesg and syslog for references to streams array handling in the drm module.

• i915_hdcp
• streams[] overflow
• drm/i915/hdcp

What your security team should do

• Prioritize kernel updates on all systems exposing Intel graphics with HDCP
• Monitor for kernel oops or panics related to i915 HDCP after applying patches
• Review graphics driver configurations to disable HDCP where not required